#!/usr/bin/python
# -*- coding: UTF-8 -*-

'''
题目：有n个人围成一圈，顺序排号。从第一个人开始报数（从1到3报数），凡报到3的人退出圈子，问最后留下的是原来第几号的那位。
'''
 
if __name__ == '__main__':
    nmax = 50
    n = int(raw_input('请输入总人数:'))
    num = []
    for i in range(n):
        num.append(i + 1)
 
    i = 0
    k = 0
    m = 0
 
    while m < n - 1:
        if num[i] != 0 : k += 1
        if k == 3:
            num[i] = 0
            k = 0
            m += 1
        i += 1
        if i == n : i = 0
 
    i = 0
    while num[i] == 0: i += 1
    print num[i]

